freebsd/usr.bin/make/arch.c

/*-
 * Copyright (c) 1988, 1989, 1990, 1993
 *	The Regents of the University of California.  All rights reserved.
 * Copyright (c) 1989 by Berkeley Softworks
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Adam de Boor.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * @(#)arch.c	8.2 (Berkeley) 1/2/94
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

/*-
 * arch.c --
 *	Functions to manipulate libraries, archives and their members.
 *
 *	Once again, cacheing/hashing comes into play in the manipulation
 * of archives. The first time an archive is referenced, all of its members'
 * headers are read and hashed and the archive closed again. All hashed
 * archives are kept on a list which is searched each time an archive member
 * is referenced.
 *
 * The interface to this module is:
 *	Arch_ParseArchive	Given an archive specification, return a list
 *				of GNode's, one for each member in the spec.
 *				FAILURE is returned if the specification is
 *				invalid for some reason.
 *
 *	Arch_Touch		Alter the modification time of the archive
 *				member described by the given node to be
 *				the current time.
 *
 *	Arch_TouchLib		Update the modification time of the library
 *				described by the given node. This is special
 *				because it also updates the modification time
 *				of the library's table of contents.
 *
 *	Arch_MTime		Find the modification time of a member of
 *				an archive *in the archive*. The time is also
 *				placed in the member's GNode. Returns the
 *				modification time.
 *
 *	Arch_MemTime		Find the modification time of a member of
 *				an archive. Called when the member doesn't
 *				already exist. Looks in the archive for the
 *				modification time. Returns the modification
 *				time.
 *
 *	Arch_FindLib		Search for a library along a path. The
 *				library name in the GNode should be in
 *				-l<name> format.
 *
 *	Arch_LibOODate		Special function to decide if a library node
 *				is out-of-date.
 *
 *	Arch_Init		Initialize this module.
 */

#include <sys/param.h>
#include <sys/types.h>
#include <ar.h>
#include <ctype.h>
#include <regex.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <utime.h>

#include "arch.h"
#include "buf.h"
#include "config.h"
#include "dir.h"
#include "globals.h"
#include "GNode.h"
#include "hash.h"
#include "make.h"
#include "targ.h"
#include "util.h"
#include "var.h"

/* Lst of archives we've already examined */
static Lst archives = Lst_Initializer(archives);

typedef struct Arch {
	char		*name;		/* Name of archive */

	/*
	 * All the members of the archive described
	 * by <name, struct ar_hdr *> key/value pairs
	 */
	Hash_Table	members;

	char		*fnametab;	/* Extended name table strings */
	size_t		fnamesize;	/* Size of the string table */
} Arch;

#if defined(__svr4__) || defined(__SVR4) || defined(__ELF__)
#define	SVR4ARCHIVES
#endif

/*-
 *-----------------------------------------------------------------------
 * Arch_ParseArchive --
 *	Parse the archive specification in the given line and find/create
 *	the nodes for the specified archive members, placing their nodes
 *	on the given list, given the pointer to the start of the
 *	specification, a Lst on which to place the nodes, and a context
 *	in which to expand variables.
 *
 * Results:
 *	SUCCESS if it was a valid specification. The linePtr is updated
 *	to point to the first non-space after the archive spec. The
 *	nodes for the members are placed on the given list.
 *
 * Side Effects:
 *	Some nodes may be created. The given list is extended.
 *
 *-----------------------------------------------------------------------
 */
ReturnStatus
Arch_ParseArchive(char **linePtr, Lst *nodeLst, GNode *ctxt)
{
	char	*cp;		/* Pointer into line */
	GNode	*gn;		/* New node */
	char	*libName;	/* Library-part of specification */
	char	*memName;	/* Member-part of specification */
	char	*nameBuf;	/* temporary place for node name */
	char	saveChar;	/* Ending delimiter of member-name */
	Boolean	subLibName;	/* TRUE if libName should have/had
				 * variable substitution performed on it */

	libName = *linePtr;

	subLibName = FALSE;

	for (cp = libName; *cp != '(' && *cp != '\0'; cp++) {
		if (*cp == '$') {
			/*
			 * Variable spec, so call the Var module to parse the
			 * puppy so we can safely advance beyond it...
			 */
			size_t	length = 0;
			Boolean	freeIt;
			char	*result;

			result = Var_Parse(cp, ctxt, TRUE, &length, &freeIt);
			if (result == var_Error) {
				return (FAILURE);
			}
			subLibName = TRUE;

			if (freeIt) {
				free(result);
			}
			cp += length - 1;
		}
	}

	*cp++ = '\0';
	if (subLibName) {
		Buffer	*buf;

		buf = Var_Subst(NULL, libName, ctxt, TRUE);
		libName = Buf_GetAll(buf, NULL);
		Buf_Destroy(buf, FALSE);
	}

	for (;;) {
		/*
		 * First skip to the start of the member's name, mark that
		 * place and skip to the end of it (either white-space or
		 * a close paren).
		 */

		/*
		 * TRUE if need to substitute in memName
		 */
		Boolean	doSubst = FALSE;

		while (*cp != '\0' && *cp != ')' &&
		    isspace((unsigned char)*cp)) {
			cp++;
		}

		memName = cp;
		while (*cp != '\0' && *cp != ')' &&
		    !isspace((unsigned char)*cp)) {
			if (*cp == '$') {
				/*
				 * Variable spec, so call the Var module to
				 * parse the puppy so we can safely advance
				 * beyond it...
				 */
				size_t	length = 0;
				Boolean	freeIt;
				char	*result;

				result = Var_Parse(cp, ctxt, TRUE,
				    &length, &freeIt);
				if (result == var_Error) {
					return (FAILURE);
				}
				doSubst = TRUE;

				if (freeIt) {
					free(result);
				}
				cp += length;
			} else {
				cp++;
			}
		}

		/*
		 * If the specification ends without a closing parenthesis,
		 * chances are there's something wrong (like a missing
		 * backslash), so it's better to return failure than allow
		 * such things to happen
		 */
		if (*cp == '\0') {
			printf("No closing parenthesis in archive "
			    "specification\n");
			return (FAILURE);
		}

		/*
		 * If we didn't move anywhere, we must be done
		 */
		if (cp == memName) {
			break;
		}

		saveChar = *cp;
		*cp = '\0';

		/*
		 * XXX: This should be taken care of intelligently by
		 * SuffExpandChildren, both for the archive and the member
		 * portions.
		 */
		/*
		 * If member contains variables, try and substitute for them.
		 * This will slow down archive specs with dynamic sources, of
		 * course, since we'll be (non-)substituting them three times,
		 * but them's the breaks -- we need to do this since
		 * SuffExpandChildren calls us, otherwise we could assume the
		 * thing would be taken care of later.
		 */
		if (doSubst) {
			char	*buf;
			char	*sacrifice;
			char	*oldMemName = memName;
			size_t	sz;
			Buffer	*buf1;

			/*
			 * Now form an archive spec and recurse to deal with
			 * nested variables and multi-word variable values....
			 * The results are just placed at the end of the
			 * nodeLst we're returning.
			 */
			buf1 = Var_Subst(NULL, memName, ctxt, TRUE);
			memName = Buf_GetAll(buf1, NULL);

			sz = strlen(memName) + strlen(libName) + 3;
			buf = emalloc(sz);

			snprintf(buf, sz, "%s(%s)", libName, memName);

			sacrifice = buf;

			if (strchr(memName, '$') &&
			    strcmp(memName, oldMemName) == 0) {
				/*
				 * Must contain dynamic sources, so we can't
				 * deal with it now.
				 * Just create an ARCHV node for the thing and
				 * let SuffExpandChildren handle it...
				 */
				gn = Targ_FindNode(buf, TARG_CREATE);

				if (gn == NULL) {
					free(buf);
					Buf_Destroy(buf1, FALSE);
					return (FAILURE);
				}
				gn->type |= OP_ARCHV;
				Lst_AtEnd(nodeLst, (void *)gn);
			} else if (Arch_ParseArchive(&sacrifice, nodeLst,
			    ctxt) != SUCCESS) {
				/*
				 * Error in nested call -- free buffer and
				 * return FAILURE ourselves.
				 */
				free(buf);
				Buf_Destroy(buf1, FALSE);
				return (FAILURE);
			}

			/* Free buffer and continue with our work. */
			free(buf);
			Buf_Destroy(buf1, FALSE);

		} else if (Dir_HasWildcards(memName)) {
			Lst	members = Lst_Initializer(members);
			char	*member;
			size_t	sz = MAXPATHLEN;
			size_t	nsz;

			nameBuf = emalloc(sz);

			Dir_Expand(memName, &dirSearchPath, &members);
			while (!Lst_IsEmpty(&members)) {
				member = Lst_DeQueue(&members);
				nsz = strlen(libName) + strlen(member) + 3;
				if (nsz > sz) {
					sz = nsz * 2;
					nameBuf = erealloc(nameBuf, sz);
				}

				snprintf(nameBuf, sz, "%s(%s)",
				    libName, member);
				free(member);
				gn = Targ_FindNode(nameBuf, TARG_CREATE);
				if (gn == NULL) {
					free(nameBuf);
					/* XXXHB Lst_Destroy(&members) */
					return (FAILURE);
				}
				/*
				 * We've found the node, but have to make sure
				 * the rest of the world knows it's an archive
				 * member, without having to constantly check
				 * for parentheses, so we type the thing with
				 * the OP_ARCHV bit before we place it on the
				 * end of the provided list.
				 */
				gn->type |= OP_ARCHV;
				Lst_AtEnd(nodeLst, gn);
			}
			free(nameBuf);
		} else {
			size_t	sz = strlen(libName) + strlen(memName) + 3;

			nameBuf = emalloc(sz);
			snprintf(nameBuf, sz, "%s(%s)", libName, memName);
			gn = Targ_FindNode(nameBuf, TARG_CREATE);
			free(nameBuf);
			if (gn == NULL) {
				return (FAILURE);
			}
			/*
			 * We've found the node, but have to make sure the
			 * rest of the world knows it's an archive member,
			 * without having to constantly check for parentheses,
			 * so we type the thing with the OP_ARCHV bit before
			 * we place it on the end of the provided list.
			 */
			gn->type |= OP_ARCHV;
			Lst_AtEnd(nodeLst, gn);
		}
		if (doSubst) {
			free(memName);
		}

		*cp = saveChar;
	}

	/*
	 * If substituted libName, free it now, since we need it no longer.
	 */
	if (subLibName) {
		free(libName);
	}

	/*
	 * We promised the pointer would be set up at the next non-space, so
	 * we must advance cp there before setting *linePtr... (note that on
	 * entrance to the loop, cp is guaranteed to point at a ')')
	 */
	do {
		cp++;
	} while (*cp != '\0' && isspace((unsigned char)*cp));

	*linePtr = cp;
	return (SUCCESS);
}

/*-
 *-----------------------------------------------------------------------
 * ArchFindArchive --
 *	See if the given archive is the one we are looking for. Called
 *	From ArchStatMember and ArchFindMember via Lst_Find with the
 *	current list element and the name we want.
 *
 * Results:
 *	0 if it is, non-zero if it isn't.
 *
 * Side Effects:
 *	None.
 *
 *-----------------------------------------------------------------------
 */
static int
ArchFindArchive(const void *ar, const void *archName)
{

	return (strcmp(archName, ((const Arch *)ar)->name));
}

/*-
 *-----------------------------------------------------------------------
 * ArchFindMember --
 *	Locate a member of an archive, given the path of the archive and
 *	the path of the desired member. If the archive is to be modified,
 *	the mode should be "r+", if not, it should be "r".  arhPtr is a
 *	poitner to the header structure to fill in.
 *
 * Results:
 *	An FILE *, opened for reading and writing, positioned at the
 *	start of the member's struct ar_hdr, or NULL if the member was
 *	nonexistent. The current struct ar_hdr for member.
 *
 * Side Effects:
 *	The passed struct ar_hdr structure is filled in.
 *
 *-----------------------------------------------------------------------
 */
static FILE *
ArchFindMember(const char *archive, const char *member, struct ar_hdr *arhPtr,
    const char *mode)
{
	FILE		*arch;	/* Stream to archive */
	int		size;	/* Size of archive member */
	const char	*cp;	/* Useful character pointer */
	char		magic[SARMAG];
	size_t		len;
	size_t		tlen;

	arch = fopen(archive, mode);
	if (arch == NULL) {
		return (NULL);
	}

	/*
	 * We use the ARMAG string to make sure this is an archive we
	 * can handle...
	 */
	if (fread(magic, SARMAG, 1, arch) != 1 ||
	    strncmp(magic, ARMAG, SARMAG) != 0) {
		fclose(arch);
		return (NULL);
	}

	/*
	 * Because of space constraints and similar things, files are archived
	 * using their final path components, not the entire thing, so we need
	 * to point 'member' to the final component, if there is one, to make
	 * the comparisons easier...
	 */
	cp = strrchr(member, '/');
	if (cp != NULL && strcmp(member, RANLIBMAG) != 0) {
		member = cp + 1;
	}
	len = tlen = strlen(member);
	if (len > sizeof(arhPtr->ar_name)) {
		tlen = sizeof(arhPtr->ar_name);
	}

	while (fread(arhPtr, sizeof(struct ar_hdr), 1, arch) == 1) {
		if (strncmp(arhPtr->ar_fmag, ARFMAG,
		    sizeof(arhPtr->ar_fmag)) != 0) {
			/*
			 * The header is bogus, so the archive is bad
			 * and there's no way we can recover...
			 */
			fclose(arch);
			return (NULL);
		}

		if (strncmp(member, arhPtr->ar_name, tlen) == 0) {
			/*
			 * If the member's name doesn't take up the entire
			 * 'name' field, we have to be careful of matching
			 * prefixes. Names are space-padded to the right, so if
			 * the character in 'name' at the end of the matched
			 * string is anything but a space, this isn't the
			 * member we sought. Additionally there may be a
			 * slash at the end of the name (System 5 style).
			 */
			if (tlen != sizeof(arhPtr->ar_name) &&
			    arhPtr->ar_name[tlen] != ' ' &&
			    arhPtr->ar_name[tlen] != '/') {
				goto skip;
			}
			/*
			 * To make life easier, we reposition the file at the
			 * start of the header we just read before we return the
			 * stream. In a more general situation, it might be
			 * better to leave the file at the actual member, rather
			 * than its header, but not here...
			 */
			fseek(arch, -sizeof(struct ar_hdr), SEEK_CUR);
			return (arch);
		}
#ifdef AR_EFMT1
		/*
		 * BSD 4.4 extended AR format: #1/<namelen>, with name as the
		 * first <namelen> bytes of the file
		 */
		if (strncmp(arhPtr->ar_name, AR_EFMT1,
		    sizeof(AR_EFMT1) - 1) == 0 &&
		    isdigit(arhPtr->ar_name[sizeof(AR_EFMT1) - 1])) {
			unsigned	elen;
			char		ename[MAXPATHLEN];

			elen = atoi(&arhPtr->ar_name[sizeof(AR_EFMT1) - 1]);
			if (elen > MAXPATHLEN) {
				fclose(arch);
				return (NULL);
			}
			if (fread(ename, elen, 1, arch) != 1) {
				fclose(arch);
				return NULL;
			}
			ename[elen] = '\0';
			/*
			 * XXX choose one.
			 */
			if (DEBUG(ARCH) || DEBUG(MAKE)) {
				printf("ArchFind: Extended format entry for "
				    "%s\n", ename);
			}
			if (strncmp(ename, member, len) == 0) {
				/* Found as extended name */
				fseek(arch, -sizeof(struct ar_hdr) - elen,
				    SEEK_CUR);
				return (arch);
			}
			fseek(arch, -elen, SEEK_CUR);
			goto skip;
		}
		#endif
	skip:
		/*
		 * This isn't the member we're after, so we need to advance the
		 * stream's pointer to the start of the next header. Files are
		 * padded with newlines to an even-byte boundary, so we need to
		 * extract the size of the file from the 'size' field of the
		 * header and round it up during the seek.
		 */
		arhPtr->ar_size[sizeof(arhPtr->ar_size) - 1] = '\0';
		size = (int)strtol(arhPtr->ar_size, NULL, 10);
		fseek(arch, (size + 1) & ~1, SEEK_CUR);
	}

	/*
	 * We've looked everywhere, but the member is not to be found. Close the
	 * archive and return NULL -- an error.
	 */
	fclose(arch);
	return (NULL);
}

#ifdef SVR4ARCHIVES
/*-
 *-----------------------------------------------------------------------
 * ArchSVR4Entry --
 *	Parse an SVR4 style entry that begins with a slash.
 *	If it is "//", then load the table of filenames
 *	If it is "/<offset>", then try to substitute the long file name
 *	from offset of a table previously read.
 *
 * Results:
 *	-1: Bad data in archive
 *	 0: A table was loaded from the file
 *	 1: Name was successfully substituted from table
 *	 2: Name was not successfully substituted from table
 *
 * Side Effects:
 *	If a table is read, the file pointer is moved to the next archive
 *	member
 *
 *-----------------------------------------------------------------------
 */
static int
ArchSVR4Entry(Arch *ar, char *name, size_t size, FILE *arch)
{
#define	ARLONGNAMES1 "//"
#define	ARLONGNAMES2 "/ARFILENAMES"
	size_t	entry;
	char	*ptr;
	char	*eptr;

	if (strncmp(name, ARLONGNAMES1, sizeof(ARLONGNAMES1) - 1) == 0 ||
	    strncmp(name, ARLONGNAMES2, sizeof(ARLONGNAMES2) - 1) == 0) {

		if (ar->fnametab != NULL) {
			DEBUGF(ARCH, ("Attempted to redefine an SVR4 name "
			    "table\n"));
			return (-1);
		}

		/*
		 * This is a table of archive names, so we build one for
		 * ourselves
		 */
		ar->fnametab = emalloc(size);
		ar->fnamesize = size;

		if (fread(ar->fnametab, size, 1, arch) != 1) {
			DEBUGF(ARCH, ("Reading an SVR4 name table failed\n"));
			return (-1);
		}
		eptr = ar->fnametab + size;
		for (entry = 0, ptr = ar->fnametab; ptr < eptr; ptr++) {
			switch (*ptr) {
			case '/':
				entry++;
				*ptr = '\0';
				break;

			case '\n':
				break;

			default:
				break;
			}
		}
		DEBUGF(ARCH, ("Found svr4 archive name table with %zu "
		    "entries\n", entry));
		return (0);
	}

	if (name[1] == ' ' || name[1] == '\0')
		return (2);

	entry = (size_t)strtol(&name[1], &eptr, 0);
	if ((*eptr != ' ' && *eptr != '\0') || eptr == &name[1]) {
		DEBUGF(ARCH, ("Could not parse SVR4 name %s\n", name));
		return (2);
	}
	if (entry >= ar->fnamesize) {
		DEBUGF(ARCH, ("SVR4 entry offset %s is greater than %zu\n",
		    name, ar->fnamesize));
		return (2);
	}

	DEBUGF(ARCH, ("Replaced %s with %s\n", name, &ar->fnametab[entry]));

	strncpy(name, &ar->fnametab[entry], MAXPATHLEN);
	name[MAXPATHLEN] = '\0';
	return (1);
}
#endif

/*-
 *-----------------------------------------------------------------------
 * ArchStatMember --
 *	Locate a member of an archive, given the path of the archive and
 *	the path of the desired member, and a boolean representing whether
 *	or not the archive should be hashed (if not already hashed).
 *
 * Results:
 *	A pointer to the current struct ar_hdr structure for the member. Note
 *	That no position is returned, so this is not useful for touching
 *	archive members. This is mostly because we have no assurances that
 *	The archive will remain constant after we read all the headers, so
 *	there's not much point in remembering the position...
 *
 * Side Effects:
 *
 *-----------------------------------------------------------------------
 */
static struct ar_hdr *
ArchStatMember(const char *archive, const char *member, Boolean hash)
{
#define	AR_MAX_NAME_LEN	    (sizeof(arh.ar_name) - 1)
	FILE		*arch;	/* Stream to archive */
	int		size;	/* Size of archive member */
	char		*cp;	/* Useful character pointer */
	char		magic[SARMAG];
	LstNode		*ln;	/* Lst member containing archive descriptor */
	Arch		*ar;	/* Archive descriptor */
	Hash_Entry	*he;	/* Entry containing member's description */
	struct ar_hdr	arh;	/* archive-member header for reading archive */
	char	memName[MAXPATHLEN + 1]; /* Current member name while hashing */

	/*
	 * Because of space constraints and similar things, files are archived
	 * using their final path components, not the entire thing, so we need
	 * to point 'member' to the final component, if there is one, to make
	 * the comparisons easier...
	 */
	cp = strrchr(member, '/');
	if (cp != NULL && strcmp(member, RANLIBMAG) != 0)
		member = cp + 1;

	ln = Lst_Find(&archives, archive, ArchFindArchive);
	if (ln != NULL) {
		char copy[AR_MAX_NAME_LEN + 1];

		ar = Lst_Datum(ln);

		he = Hash_FindEntry(&ar->members, member);
		if (he != NULL) {
			return (Hash_GetValue(he));
		}

		/* Try truncated name */
		strncpy(copy, member, AR_MAX_NAME_LEN);
		copy[AR_MAX_NAME_LEN] = '\0';

		if ((he = Hash_FindEntry(&ar->members, copy)) != NULL)
			return (Hash_GetValue(he));
		return (NULL);
	}

	if (!hash) {
		/*
		 * Caller doesn't want the thing hashed, just use ArchFindMember
		 * to read the header for the member out and close down the
		 * stream again. Since the archive is not to be hashed, we
		 * assume there's no need to allocate extra room for the header
		 * we're returning, so just declare it static.
		 */
		static struct ar_hdr sarh;

		arch = ArchFindMember(archive, member, &sarh, "r");
		if (arch == NULL) {
			return (NULL);
		}
		fclose(arch);
		return (&sarh);
	}

	/*
	 * We don't have this archive on the list yet, so we want to find out
	 * everything that's in it and cache it so we can get at it quickly.
	 */
	arch = fopen(archive, "r");
	if (arch == NULL) {
		return (NULL);
	}

	/*
	 * We use the ARMAG string to make sure this is an archive we
	 * can handle...
	 */
	if (fread(magic, SARMAG, 1, arch) != 1 ||
	    strncmp(magic, ARMAG, SARMAG) != 0) {
		fclose(arch);
		return (NULL);
	}

	ar = emalloc(sizeof(Arch));
	ar->name = estrdup(archive);
	ar->fnametab = NULL;
	ar->fnamesize = 0;
	Hash_InitTable(&ar->members, -1);
	memName[AR_MAX_NAME_LEN] = '\0';

	while (fread(&arh, sizeof(struct ar_hdr), 1, arch) == 1) {
		if (strncmp(arh.ar_fmag, ARFMAG, sizeof(arh.ar_fmag)) != 0) {
			/*
			 * The header is bogus, so the archive is bad
			 * and there's no way we can recover...
			 */
			goto badarch;
		}
		/*
		 * We need to advance the stream's pointer to the start of the
		 * next header. Files are padded with newlines to an even-byte
		 * boundary, so we need to extract the size of the file from the
		 * 'size' field of the header and round it up during the seek.
		 */
		arh.ar_size[sizeof(arh.ar_size) - 1] = '\0';
		size = (int)strtol(arh.ar_size, NULL, 10);

		strncpy(memName, arh.ar_name, sizeof(arh.ar_name));
		for (cp = &memName[AR_MAX_NAME_LEN]; *cp == ' '; cp--) {
			;
		}
		cp[1] = '\0';

#ifdef SVR4ARCHIVES
		/*
		 * svr4 names are slash terminated. Also svr4 extended AR
		 * format.
		 */
		if (memName[0] == '/') {
			/*
			 * svr4 magic mode; handle it
			 */
			switch (ArchSVR4Entry(ar, memName, size, arch)) {

			case -1:  /* Invalid data */
				goto badarch;

			case 0:	  /* List of files entry */
				continue;
			default:  /* Got the entry */
				break;
			}
		} else {
			if (cp[0] == '/')
				cp[0] = '\0';
		}
#endif

#ifdef AR_EFMT1
		/*
		 * BSD 4.4 extended AR format: #1/<namelen>, with name as the
		 * first <namelen> bytes of the file
		 */
		if (strncmp(memName, AR_EFMT1, sizeof(AR_EFMT1) - 1) == 0 &&
		    isdigit(memName[sizeof(AR_EFMT1) - 1])) {
			unsigned elen = atoi(&memName[sizeof(AR_EFMT1) - 1]);

			if (elen > MAXPATHLEN)
				goto badarch;
			if (fread(memName, elen, 1, arch) != 1)
				goto badarch;
			memName[elen] = '\0';
			fseek(arch, -elen, SEEK_CUR);
			/*
			 * XXX Multiple levels may be asked for, make this
			 * conditional on one, and use DEBUGF.
			 */
			if (DEBUG(ARCH) || DEBUG(MAKE)) {
				fprintf(stderr, "ArchStat: Extended format "
				    "entry for %s\n", memName);
			}
		}
#endif

		he = Hash_CreateEntry(&ar->members, memName, NULL);
		Hash_SetValue(he, emalloc(sizeof(struct ar_hdr)));
		memcpy(Hash_GetValue(he), &arh, sizeof(struct ar_hdr));
		fseek(arch, (size + 1) & ~1, SEEK_CUR);
	}

	fclose(arch);

	Lst_AtEnd(&archives, ar);

	/*
	 * Now that the archive has been read and cached, we can look into
	 * the hash table to find the desired member's header.
	 */
	he = Hash_FindEntry(&ar->members, member);

	if (he != NULL) {
		return (Hash_GetValue (he));
	} else {
		return (NULL);
	}

  badarch:
	fclose(arch);
	Hash_DeleteTable(&ar->members);
	free(ar->fnametab);
	free(ar);
	return (NULL);
}

/*-
 *-----------------------------------------------------------------------
 * Arch_Touch --
 *	Touch a member of an archive.
 *
 * Results:
 *	The 'time' field of the member's header is updated.
 *
 * Side Effects:
 *	The modification time of the entire archive is also changed.
 *	For a library, this could necessitate the re-ranlib'ing of the
 *	whole thing.
 *
 *-----------------------------------------------------------------------
 */
void
Arch_Touch(GNode *gn)
{
	FILE		*arch;	/* Archive stream, positioned properly */
	struct ar_hdr	arh;	/* Current header describing member */
	char		*p1, *p2;

	arch = ArchFindMember(Var_Value(ARCHIVE, gn, &p1),
	    Var_Value(TARGET, gn, &p2), &arh, "r+");
	free(p1);
	free(p2);

	if (arch != NULL) {
		snprintf(arh.ar_date, sizeof(arh.ar_date), "%-12ld", (long)now);
		fwrite(&arh, sizeof(struct ar_hdr), 1, arch);
		fclose(arch);
	}
}

/*-
 *-----------------------------------------------------------------------
 * Arch_TouchLib --
 *	Given a node which represents a library, touch the thing, making
 *	sure that the table of contents also is touched.
 *
 * Results:
 *	None.
 *
 * Side Effects:
 *	Both the modification time of the library and of the RANLIBMAG
 *	member are set to 'now'.
 *
 *-----------------------------------------------------------------------
 */
void
Arch_TouchLib(GNode *gn)
{
#ifdef RANLIBMAG
	FILE		*arch;	/* Stream open to archive */
	struct ar_hdr	arh;	/* Header describing table of contents */
	struct utimbuf	times;	/* Times for utime() call */

	arch = ArchFindMember(gn->path, RANLIBMAG, &arh, "r+");
	if (arch != NULL) {
		snprintf(arh.ar_date, sizeof(arh.ar_date),
		    "%-12ld", (long) now);
		fwrite(&arh, sizeof(struct ar_hdr), 1, arch);
		fclose(arch);

		times.actime = times.modtime = now;
		utime(gn->path, &times);
	}
#endif
}

/*-
 *-----------------------------------------------------------------------
 * Arch_MTime --
 *	Return the modification time of a member of an archive, given its
 *	name.
 *
 * Results:
 *	The modification time(seconds).
 *	XXXHB this should be a long.
 *
 * Side Effects:
 *	The mtime field of the given node is filled in with the value
 *	returned by the function.
 *
 *-----------------------------------------------------------------------
 */
int
Arch_MTime(GNode *gn)
{
	struct ar_hdr	*arhPtr;	/* Header of desired member */
	int		modTime;	/* Modification time as an integer */
	char		*p1, *p2;

	arhPtr = ArchStatMember(Var_Value(ARCHIVE, gn, &p1),
	    Var_Value(TARGET, gn, &p2), TRUE);
	free(p1);
	free(p2);

	if (arhPtr != NULL) {
		modTime = (int)strtol(arhPtr->ar_date, NULL, 10);
	} else {
		modTime = 0;
	}

	gn->mtime = modTime;
	return (modTime);
}

/*-
 *-----------------------------------------------------------------------
 * Arch_MemMTime --
 *	Given a non-existent archive member's node, get its modification
 *	time from its archived form, if it exists.
 *
 * Results:
 *	The modification time.
 *
 * Side Effects:
 *	The mtime field is filled in.
 *
 *-----------------------------------------------------------------------
 */
int
Arch_MemMTime(GNode *gn)
{
	LstNode	*ln;
	GNode	*pgn;
	char	*nameStart;
	char	*nameEnd;

	for (ln = Lst_First(&gn->parents); ln != NULL; ln = Lst_Succ(ln)) {
		pgn = Lst_Datum(ln);

		if (pgn->type & OP_ARCHV) {
			/*
			 * If the parent is an archive specification and is
			 * being made and its member's name matches the name of
			 * the node we were given, record the modification time
			 * of the parent in the child. We keep searching its
			 * parents in case some other parent requires this
			 * child to exist...
			 */
			nameStart = strchr(pgn->name, '(') + 1;
			nameEnd = strchr(nameStart, ')');

			if (pgn->make && strncmp(nameStart, gn->name,
			    nameEnd - nameStart) == 0) {
				gn->mtime = Arch_MTime(pgn);
			}
		} else if (pgn->make) {
			/*
			 * Something which isn't a library depends on the
			 * existence of this target, so it needs to exist.
			 */
			gn->mtime = 0;
			break;
		}
	}
	return (gn->mtime);
}

/*-
 *-----------------------------------------------------------------------
 * Arch_FindLib --
 *	Search for a named library along the given search path.
 *
 * Results:
 *	None.
 *
 * Side Effects:
 *	The node's 'path' field is set to the found path (including the
 *	actual file name, not -l...). If the system can handle the -L
 *	flag when linking (or we cannot find the library), we assume that
 *	the user has placed the .LIBRARIES variable in the final linking
 *	command (or the linker will know where to find it) and set the
 *	TARGET variable for this node to be the node's name. Otherwise,
 *	we set the TARGET variable to be the full path of the library,
 *	as returned by Dir_FindFile.
 *
 *-----------------------------------------------------------------------
 */
void
Arch_FindLib(GNode *gn, Lst *path)
{
	char	*libName;	/* file name for archive */
	size_t	sz;

	sz = strlen(gn->name) + 4;
	libName = emalloc(sz);
	snprintf(libName, sz, "lib%s.a", &gn->name[2]);

	gn->path = Dir_FindFile(libName, path);

	free(libName);

#ifdef LIBRARIES
	Var_Set(TARGET, gn->name, gn);
#else
	Var_Set(TARGET, gn->path == NULL ? gn->name : gn->path, gn);
#endif /* LIBRARIES */
}

/*-
 *-----------------------------------------------------------------------
 * Arch_LibOODate --
 *	Decide if a node with the OP_LIB attribute is out-of-date. Called
 *	from Make_OODate to make its life easier, with the library's
 *	graph node.
 *
 *	There are several ways for a library to be out-of-date that are
 *	not available to ordinary files. In addition, there are ways
 *	that are open to regular files that are not available to
 *	libraries. A library that is only used as a source is never
 *	considered out-of-date by itself. This does not preclude the
 *	library's modification time from making its parent be out-of-date.
 *	A library will be considered out-of-date for any of these reasons,
 *	given that it is a target on a dependency line somewhere:
 *	    Its modification time is less than that of one of its
 *		  sources (gn->mtime < gn->cmtime).
 *	    Its modification time is greater than the time at which the
 *		  make began (i.e. it's been modified in the course
 *		  of the make, probably by archiving).
 *	    The modification time of one of its sources is greater than
 *		  the one of its RANLIBMAG member (i.e. its table of contents
 *		  is out-of-date). We don't compare of the archive time
 *		  vs. TOC time because they can be too close. In my
 *		  opinion we should not bother with the TOC at all since
 *		  this is used by 'ar' rules that affect the data contents
 *		  of the archive, not by ranlib rules, which affect the
 *		  TOC.
 *
 * Results:
 *	TRUE if the library is out-of-date. FALSE otherwise.
 *
 * Side Effects:
 *	The library will be hashed if it hasn't been already.
 *
 *-----------------------------------------------------------------------
 */
Boolean
Arch_LibOODate(GNode *gn)
{
#ifdef RANLIBMAG
	struct ar_hdr	*arhPtr;	/* Header for __.SYMDEF */
	int		modTimeTOC;	/* The table-of-contents's mod time */
#endif

	if (OP_NOP(gn->type) && Lst_IsEmpty(&gn->children)) {
		return (FALSE);
	}
	if (gn->mtime > now || gn->mtime < gn->cmtime) {
		return (TRUE);
	}

#ifdef RANLIBMAG
	arhPtr = ArchStatMember(gn->path, RANLIBMAG, FALSE);

	if (arhPtr != NULL) {
		modTimeTOC = (int)strtol(arhPtr->ar_date, NULL, 10);

		/* XXX choose one. */
		if (DEBUG(ARCH) || DEBUG(MAKE)) {
			printf("%s modified %s...", RANLIBMAG,
			    Targ_FmtTime(modTimeTOC));
		}
	    	return (gn->cmtime > modTimeTOC);
	} else {
		/*
		 * A library w/o a table of contents is out-of-date
		 */
		if (DEBUG(ARCH) || DEBUG(MAKE)) {
			printf("No t.o.c....");
		}
		return (TRUE);
	}
#else
	return (gn->mtime == 0);	/* out-of-date if not present */
#endif
}

/*-
 *-----------------------------------------------------------------------
 * Arch_Init --
 *	Initialize things for this module.
 *
 * Results:
 *	None.
 *
 *-----------------------------------------------------------------------
 */
void
Arch_Init(void)
{
}